Such a radiating element operates simultaneously in two frequency bands, which frequency bands may, in particular, be close together, and in each frequency band, the element is capable of generating two orthogonal polarizations: linear or circular.
The advantage of of such an element is that it provides good signal separation performance between one frequency band and the other, in particular when the bands are close together.
It may also be used in any waveguide element that needs to operate at two separate frequencies and requires compact excitation from a TEM line feed (e.g. a coaxial line, a three-plate line, or a microstrip).
In general, prior art systems capable of operating at two frequencies require:
either a wideband radiating element and a system of diplexing filters for rejecting one frequency band or the other;
or else the superposition of two types of radiating element each operating in its own frequency band. The further apart the radiating zones of these elements, the lower the coupling between them. They are therefore difficult to improve without increasing the dimensions of one or other of the radiating elements.
In the superposition case, there is a difference between the equivalent radiating areas and this is poorly adapted to a sampling antenna, for example.
The object of the invention is to mitigate these various drawbacks.